1. Field of the Invention
This invention relates to a side guide for a feeder section of a mail handling machine, and in particular to a side guide capable of eliminating mailpiece skew for large and small sized mailpieces.
2. Description of the Related Art
U.S. Pat. No. 4,930,764 issued to Holbrook et al., and U.S. Pat. No. 5,112,037 issued to Holbrook, are both assigned to the assignee of the instant application and are each directed to a front end feeder for a mail handling machine. In each of the aforementioned patents, which are hereby incorporated by reference, the front end feeder includes a hopper region with a deck which is substantially fiat and in which is embedded a series of drive wheels which are angled toward a rear registration wall. Moreover, the deck is angled slightly backwards and slightly towards the rear registration wall. When a stack of envelopes intended to be sealed and posted in the mailing machine are loaded into the hopper region, the function of the front feeder is to pre-shingle the mail while concurrently moving it downstream toward a singulator located downstream of the hopper region. The orientation of the deck and the drive wheels are designed to ensure that the mailpieces being processed in the mailing machine are maintained in registration with the rear registration wall as they approach and enter the singulator. Furthermore, U.S. Pat. No. 5,112,037 discloses a plurality of fixed steps which are disposed on the top surface of the deck to provide additional tilting and guidance of wide mailpieces to prevent mis-registration.
While the apparatus described in the above-identified patents perform extremely well for most mailpieces being processed through the mail handling machine, experience has shown that some very small and thin pieces of mail tend to obtain a natural curve therein such that these mailpieces are not adequately urged toward the registration wall and are subsequently presented to the singulator in a skewed orientation. Moreover, it is conventional for large pieces of mail such as, for example, those measuring nine inches by twelve inches to be fed through the mail handling machine along their longitudinal direction. The previously identified patents register these large pieces of mail quite well. However, users of mail handling machines are ever increasingly sending these large pieces of mail through the mail handling machine along the direction of their shorter length. Mail which is processed through the mail handling machine in this fashion is referred to as "portrait mail". In this situation, the drive wheels are sometimes ineffective in registering the portrait mail against the rear registration wall such that the portrait mail is presented to the singulator in a skewed orientation. In both of the above-mentioned situations, if the mailpiece is presented to the singulator in a skewed orientation, it will pass through subsequent operational sections (for example, flap moistening, flap sealing, weighing, indicia printing) of the mail handling machine in a skewed orientation thereby negatively impacting the operation of these subsequent operational sections. Accordingly, a device is needed to ensure that small, thin pieces of mail and large pieces of mail processed as portrait mail are assuredly registered against the rear registration wall of a mail handling machine. However, since the drive wheels extend above the surface of the deck of the front feeder, they present a significant obstacle in designing a side guide which can be used to register a full spectrum of mailpiece widths such as, for example, those ranging from four inches to thirteen and one-half inches in width. Thus, a side guide is needed which can be adjusted to accommodate the full range of mailpiece widths while avoiding interference with the drive wheels.